Method for suppression of heat radiation

ABSTRACT

A radiation field is attenuated by dispersing in it a cloud of discrete particles. Several dust dispensers are disclosed for this purpose.

7 United States Patent [a Regelson et al.

[ 1 Jan. 23, 1973 METHOD FOR SUPPRESSION OF HEAT RADIATION [75]lnventorsz Ephraim Regelson, Kensington, Md.; Howard I. Sumnicht, ChinaLake; John D. Crecelius, Ridgecrest, both of Calif.

[73] Assignee: The United States of Aineric a as represented by theSecretary of the Navy [22] Filedz 6e11, T969 [21] App1.No.: 866,073

[52] [1.8. CI. ..60/39.02, 60/395, 60/271, 60/3909 [51] Int. Cl ..F02g3/00 [58] Field of Search ..60/39.02, 204, 39.66; 222/399, 222/373, 152,335; 244/136, 3.16; 239/290 Primary Examiner-Samuel FeinbergAttorney-Edgar J. Brower, Roy Miller and Gerald F. Baker [57] ABSTRACT Aradiation field is attenuated by dispersing in it a cloud of discreteparticles. Several dust dispensers are disclosed for this purpose.

1 Claim, 6 Drawing Figures PATENTEnJmzmm FIG.

SHEET 1 BF 2 METHOD FOR SUPPRESSION OF HEAT RADIATION BACKGROUND OF THEINVENTION In the past, exhaust area radiation has been attenuated withvarying degrees of success by the use of cumbersome covers, shields orother modifications to the aircraft, usually at the sacrifice ofincreased weight and decreased aerodynamic stability.

It has been found, with the use of this invention, that attenuation ofradiation has been greater with less added weight and practically noeffect on aerodynamic stability.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a sideview, in schematic form, ofa first embodiment of the invention;

FIG. 2 is a side view, in schematic form, of a second embodiment of theinvention;

FIG. 2A is a view looking in the direction of the arrow 2A in FIG. 2.

FIG. 3 is a side view of a third modification of the invention;

FIG. 3A is a view taken along line 3A-3A of FIG. 3; and

FIG. 4 is a perspective view of still a fourth embodiment of theinvention. I

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows a very simple dustdispenser comprising a dust reservoir 12 communicating through a pipe 14with a dispenser manifold 16. Dispensing of the dust 13 from reservoir12 is controlled by means of a valve 18 which is preferably electricallyoperable. It will be apparent from the drawing that when the valve 18 isopened ram air will enter through the port 20 and thence through holes22 into the mixing chamber of reservoir 12 to fluidize the dustparticles. The force of the air will then continue carrying particles ofdust along the lines of arrows 24 into the end 26 of pipe 14 andprogress to the manifold 16. Fluidized dust is then dispensed through aplurality of venturis 28 for maximum dispersion.

In the FIG. 2 device, 10', the ram air entering port 20 does not mixwith the dust 13 but acts upon a rubber diaphragm which pushes upon thedust 13 to move it toward a feed screw 17. Feed screw 17 forces the dustfrom the reservoir 12 into a mixing area 19 where further ram air,moving along the lines of arrow 21, causes the fluidization of the dustand forces the dust along a conduit 23 to manifold 16' which manifolddovetails into a semicircular array of dust outlets 30 more clearly seenwith reference to FIG. 2A.

Feed screw 17 is rotated by a motor 32 through gear box 34 under thecontrol of controller 36 and hand operable switch 38, for example.

The dispenser 40 shown in FIG. 3, like the FIG. 1 embodiment, dispensesthe dust through a plurality of venturis 28 from a manifold 46 when dustis delivered along pipe 44. A control valve 42 regulates ram air throughopening 41 and hole 45 through the dust chamber 43. When control valve42 is opened and pressure is raised in chamber 43, a pressure actuateddiaphragm 52 acts against return spring 54 to pull the plug 48 fromopening 49 through coupling rod 55, thus allowing fluidized dust to passthrough conduit 44 and into manifold pipe 46.

The venturi 28' are shown in this modification arranged about asemicircle as shown in FIG. 3A and the use of two such units can give afull 360 range.

In the FIG. 4 device, alternative passageways 51, 53 are filled withdust (powder) and the two ends sealed. The forward end 62 is closed by areleasable band 64 and the aft end 53 by a communicating passageway 65.An explosive device 58, for example, is used to remove band 64,uncovering holes 57, admitting ram air to passageways 51. Air circulatesthrough passageways 51 and 53 to emerge from holes 59 through skin 56into the surrounding airstream.

What is claimed is:

l. The method of attenuating the heat radiation signature of a heatexhausting vehicle engine, comprisstoring on said vehicle a supply ofpowdered material; temporally fluidizing said powdered material withcompressed air;

conveying a quantity of said fluidized powder to the vicinity of a heatradiating portion of said vehicle or engine; and

dispersing a quantity of said powder into the immediate area surroundingsaid heat radiating portion.

1. The method of attenuating the heat radiation signature of a heatexhausting vehicle engine, comprising; storing on said vehicle a supplyof powdered material; temporally fluidizing said powdered material withcompressed air; conveying a quantity of said fluidized powder to thevicinity of a heat radiating portion of said vehicle or engine; anddispersing a quantity of said powder into the immediate area surroundingsaid heat radiating portion.